Development of a harmonized patient-reported outcome questionnaire to assess myelofibrosis symptoms in clinical trials

•Myelofibrosis is a highly symptomatic myeloproliferative neoplasm•Myelofibrosis causes both splenomegaly-related and constitutional symptoms•The MFSAF v4.0 assesses the severity of seven core symptoms of myelofibrosis•The MFSAF v4.0′s 24-h and 7-day recall formats are available for use in trials•Research is needed to confirm the measurement characteristics of the MFSAF v4.0 Along with reducing spleen size, relieving symptom severity is a key objective of the treatment of myelofibrosis (MF). Several questionnaires have been developed for patient self-report of MF symptoms in clinical trials and each includes unique instructions, items, and/or response scales. This variability in questionnaire content increases uncertainty; it is unclear which questionnaire is the most appropriate for assessing MF symptoms and it makes comparisons across trials difficult. The Patient-Reported Outcome (PRO) Consortium’s MF Working Group (WG) was established to review existing MF symptom questionnaires and to develop a harmonized, consensus-based PRO questionnaire for use in future MF trials. The WG focused on the seven core symptoms of MF: fatigue, night sweats, pruritus, abdominal discomfort, pain under the ribs on the left side, early satiety, and bone pain. The resulting Myelofibrosis Symptom Assessment Form version 4.0 (MFSAF v4.0) asks respondents to report symptom severity at its worst for each of the seven items on a 0 (Absent) to 10 (Worst Imaginable) numeric rating scale. The MFSAF v4.0, for which there are 24-h and 7-day recall formats, will be maintained and licensed by the Critical Path Institute and made publicly available for use in future clinical trials.